Apparatus for the manufacture of coated paper



April 20, 1937. UQNG 2,077,726

APPARATUS FOR THE MANUFACTURE OF COATED PAPER Original Filed April 1,1953 2 Sheets-Sheet 1 M AETORNEZ D. D. UONG April 20, 1937.

APPARATUS FOR THE MANUFACTURE OF COATED RAPER Original Filed April 1,1933 2 Sheets-Sheet 2 IN V EN TOR.

J I 6/ B 602 0250 M "ZTTOR/VEYS;

Patented A r.- 20, 1937 2,011,12 srrsaarusron 'rnn mmnmc'runn or cos-ranmesa Diong D. Uong, Fltchburg, Masa, assignor to Fltchburg laperCompany, Fitchburg, Mass a corporation of Massachusetts l applicationApril 1, 1933, Serial No. 663,966. Divided and this application August17, 1935, Serial No. 36,623

4mm. (cur-4a) This'applicatlon is a division of my prior ap- Fig. 4 is adetail side elevation of a portion plication Serial No. 663,966, filedby me April of one of the feeding plates;

1, 1933. Fig. 5 is an end view, looking in the direction of Thisinvention relates to the manufacture of the arrow 5 in Fig. 4, and 1paper presenting a coated surface at one or Fig. 6 is a detail view,looking in the direction both sides thereof. Such coated papers arecomof the arrow 6 in Fig. 5. monly produced by the application of asuitable Referring to Fig. 1, I have shown portions of a coatingmaterial to previously formed paper, and paper making machine of a usualtype and having in the usual'commercial practice a liquid coatingaFourdrinier section A, a press roll section B material has been appliedto the paper after and a drying section C. The Fourdrinier section thepaper has been dried and removed from the paper making machine. Suchapplication ofliquid coating material to substantially dry paperinvolves a separate and additional coating operation as well as a seconddrying operation, all at substantial additional expense.

It is the general object of my invention to provide apparatus forproducing a coated paper by the application of a coating material inpowdered form to a web of paper while it is still in the paper makingmachine and before the drying thereof is completed.

Preferably I apply the powder to the web at a. point where the web stillcontains a substantial amount of water, a condition found at the suctionboxes and to a less extent at the press rolls. It may at times, however,be desirable to apply the powdered coating material even later in thepaper making process, as for instance at a point between sections ofdrying cylinders.

In any event, the powdered coating material is to be applied uniformlyto the paper web while it still contains suilicient moisture to coactwith the powdered material and produce an effective coating on thepaper.

A further object of my invention is to provide improved powder feedingmechanism for thus uniformly applying a powdered coating material to apaper web in a paper making machine.

My invention further relates to arrangements and combinations of partswhich will be hereinafter described and more particularly pointed out inthe appended claims.

A preferred form of the invention is shown in the drawings, in whichFig. 1 is a diagrammatic side elevation of portions of a paper makingmachine having my invention applied thereto;

Fig. 2 is a sectional side-elevation of a preferred form of mechanismfor applying the powdered coating material to the moist web;

Fig, 3 is a sectional elevation of the coatingapplying mechanism, takenalong the line 3-3 in Fig. 2;

conveyor Ill on which the paper material or pulp is deposited andthrough which a portion of the water escapes or is sucked away.

The apron i0 and partially formed paper web W passes over a series ofsuction boxes H, under a dandy roll l2, and around-a. larger or couchroll iii. The partially formed paper web W then passes betweensuccessive pairs of press rolls l4, l5 and I6 in the press roll sectionB,after which the'web passes around a series of drying rolls orcylinders 20 in the drying section C, the cylheated to remove asubstantial portion of the moisture still remaining in the web W.

The paper-making machine thus briefly described is of a usual commercialtype and in itself constitutes no part of my present invention, whichrelates particularly to the mechanism M for applying coating material inpowdered form to the paper web W as it passes through the papermakingmachine.

The location of the mechanism M in the papermaking machine is subject tosomewhat wide variation but as at present practiced, I preferably mountthe mechanism M so that the powdered material is applied to the paperweb W as it passes over the first pair of suction boxes H, at whichpoint the paper web' may comprise eighty percent, or more of water.

While the position above the suction boxes is at present favored, themechanism M may, if desired, be so mounted as to deliver the powderedcoating material to the paper web W as it machine. Such a location isindicated in dotted lines in Fig. l, the coating mechanism M being webas it passes from the first pair of press rolls ll to the second pair ofpress rolls l5, at which point the web W contains substantially lessmoisture than at the suction boxes.

I may also position the coating mechanism entirely beyond the press rollsection, as indicated in dotted lines at M in Fig. 1, at which point Acomprises a fine mesh wire screen apron or inders 20 beingof relativelylarge size and steampasses through the press'roll section B of thepositioned to apply the coating material to the the moisture content ofthe paper web may be as low as twenty percent.

The location of the coating mechanism will be selected with reference tothe paper stock, the coating material, the type of surface to beproduced, and other operating conditions.

In Figs. 2 to 6 I have shown the details of the form of coatingmechanism M which I have devised for applying powdered coating materialto the paper web W. As shown in the drawings, the coating mechanism Mcomprises a casing 22 mounted on suitable supporting frame members 23adapted to be easily secured to the main frame at the paper-makingmachine at a desired loca- A pair of distributing rolls 24 and 25 aresupported in bearings 26 on the frame members 23 and are rotated by thedriving belt 21 in the direction of the arrows a in Fig. 2. A hopper 30.is mounted above the casing 22 and is provided with feed plates 32,adJustably secured to blocks 34 and 35 which in turn are mounted onpairs of slide bars 36 which function as fixed guides for the blocks 34and 35.

The blocks 34 at each side of the hopper are connected by links 40 and4| to eccentric pins 42 rotated with a pulley 43 by a belt 44. As thepulley 43 is rotated, it will be obvious that the feed plates 32 aregiven slight reciprocating movements in reversed directions, thustending to evenly distribute the powdered material lengthwise of theplates and to feed the material downward through the relatively narrowopening between the lower edges of the feed plates 32. The width of thisopening may be adjusted by adjusting the plates 32 in the blocks 34 and35, for

which purpose adjusting screws 45 are provided.

The feed plates 32 converge downward as shown in Fig. 2, and the loweredges of the plates are preferably beveled as indicated at 46 in Fig. 5.The lower portions of the plates 32 are also preferably grooved asindicated at 41 in Figs. 4 and 6, and the beveled edges 46 arepreferably provided with finer grooves as indicated at 43 in Figs. 4 and6. As the plates 32 are relatively reciprocated, the grooved lowerportions of the platestend to pulverize the powdered coating material,should any lumps or hard portions occur therein.

By the use of these reciprocating grooved feed plates a fine uniformstream of powdered material is delivered to the roll 24 within thecasing 22, and a considerable portion of this material is passed alongby the roll 24 to the roll 25, as indicated at Fig. 2.

After leaving the roll 25, the powdered material circulates in differentdirections within the casing 22 and is finally deposited in asubstantially uniform manner on the moist surface of the paper web W.The rolls 24 and 25 are preferably provided with knurled surfaces asindicated in Fig. 3 for more eflectively'advancing and distributing thepowdered material.

It will be evident from the foregoing description'that the mechanism Mfor applyina he P dered material to the paper web is a self-containedunit which may be readily mounted in any convenient position in a.paper-making machine, as indicated at M, M, M and M in Fig.

1, the particular position selected depending on the nature of theproduct and desired coating and on the operating conditions.

It is deemed essential that the paper web should have sufllcientsubstance so that the powdered material. will remain largely on thesurface of the web, and furthermore that the. web shall containsufilcient moisture to coact with the powdered material in producing aneffective coating. Under ordinary conditions the moisture content willrun from twenty to ninety percent in the web at the point of powderapplication. The powdered material itself may be varied to suitoperating conditions and the particular type of coating desired, butwill commonly consist largely of an adhesive material mixed with someform of pigment of different colors.

Having thus described my invention and the advantages thereof, I do notwish to be limited to the details herein disclosed, otherwise than asset forth in the claims, but what I claim is:-

1. A powder-applying mechan'ismfor a papermaking machine comprising acasing, a hopper mounted thereon, feeding devices for said hopper, and apair of distributing rolls mounted in said casing and substantiallyspaced from the side walls thereof, said rolls having roughened andsubstantially continuous peripheral surfaces and being positivelyrotated in the same direction, one of said-rolls being positioneddirectly in the path of the. falling powder and being effective toagitate and divert said powder and the other roll beingmounted at oneside of said first roll and being horizontally displaced therefrom inthe direction in which the falling pow-- der is diverted by engagementwith said first roll and receiving portions of said diverted fallingpowder directly from said first roll.

2. A powder-applying mechanism for a papermaking machine comprising acasing, a hopper mounted thereon, and feeding devices for said powdercomprising a. pair of adjacent plates mounted at opposite sides of saidhopper and means to reciprocate said plates longitudinally, said plateshaving a plurality of substantially vertical grooves formed in theirinner surfaces and lower end surfaces.

3. A powder-applying mechanism for a. papermaking machine comprising acasing, a hopper mounted thereon, and feeding devicesfor said powdercomprising a pair of adjacent and substantially vertically groovedplates mounted at opposite sides of said hopper and means to reciprocatesaid plates longitudinally and to cause said plates to movesimultaneously in opposite directions.

4. A powder-applying mechanism for a papermaking machine comprising acasing, a hopper mounted thereon, and feeding devices for said powdercomprising a pair of adjacent and substantially vertically groovedplates mounted at opposite sides of said hopper, means to reciprocatesaid plates longitudinally, said plates being inclined relatively toeach other, and means to adjust said plates in the planes thereof tovary the powder delivery opening between said plates.

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